[gtk/mcatanzaro/#2424] window: prepare for window destruction after gtk_window_close()

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 4bdea87e533c208a46deb8a27894137b0b4c6da6
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Mon Feb 10 17:14:18 2020 -0600

    window: prepare for window destruction after gtk_window_close()
    
    Epiphany is doing something weird after calling gtk_window_close(),
    because by the time the callback executes, the window has no GdkWindow.
    Let's protect the GtkWindow for the callback, and also guard against
    NULL GdkWindow.
    
    Fixes #2424

 gtk/gtkwindow.c | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 7229518900..4664d67560 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -1310,22 +1310,34 @@ _gtk_window_toggle_maximized (GtkWindow *window)
     gtk_window_maximize (window);
 }
 
-static gboolean
-send_delete_event (gpointer data)
+static void
+send_delete_event (GtkWindow *window)
 {
-  GtkWidget *window = data;
-  GtkWindowPrivate *priv = GTK_WINDOW (window)->priv;
-
   GdkEvent *event;
+  GdkWindow *gdk_window;
 
-  event = gdk_event_new (GDK_DELETE);
+  gdk_window = _gtk_widget_get_window (GTK_WIDGET (window));
+  if (gdk_window)
+    {
+      event = gdk_event_new (GDK_DELETE);
+      event->any.window = g_object_ref (gdk_window);
+      event->any.send_event = TRUE;
 
-  event->any.window = g_object_ref (_gtk_widget_get_window (window));
-  event->any.send_event = TRUE;
-  priv->delete_event_handler = 0;
+      gtk_main_do_event (event);
+
+      gdk_event_free (event);
+    }
+}
 
-  gtk_main_do_event (event);
-  gdk_event_free (event);
+static gboolean
+do_send_delete_event (gpointer data)
+{
+  GtkWindow *window = data;
+  GtkWindowPrivate *priv = window->priv;
+
+  priv->delete_event_handler = 0;
+  send_delete_event (window);
+  g_object_unref (window);
 
   return G_SOURCE_REMOVE;
 }
@@ -1348,7 +1360,7 @@ gtk_window_close (GtkWindow *window)
   if (!_gtk_widget_get_realized (GTK_WIDGET (window)))
     return;
 
-  window->priv->delete_event_handler = gdk_threads_add_idle_full (G_PRIORITY_DEFAULT, send_delete_event, 
window, NULL);
+  window->priv->delete_event_handler = gdk_threads_add_idle_full (G_PRIORITY_DEFAULT, do_send_delete_event, 
g_object_ref (window), NULL);
   g_source_set_name_by_id (window->priv->delete_event_handler, "[gtk+] send_delete_event");
 }